You often see French and Spanish-speaking actors (like Gerard Depardieu and Penelope Cruz) making it big in Hollywood, but it's very rare to see an English-speaking actor doing the journey the other way.
However, that's what Kristen Scott Thomas has done in I've Loved You So Long (Il Y a Longtemps Que Je T'Aime ), a French film which won a BAFTA earlier this year for the Best Foreign Film.
She plays Juliette, who at the beginning of the film returns to live with her younger sister after an absence of 15 years.
We quickly learn that the reason for this prolonged absence is that she has been in prison for a terrible crime, but although the details of the crime do emerge over the course of the film, the reason why she did it is revealed only at the very end.
The main body of the film centres on Juliette coming to terms with her new surroundings through a variety of relationships with everyone from her parole officer to a man she picks up in a bar to (more significantly) her sister Lea, Lea's father-in-law and Lea's fellow university lecturer Michel.
It really is an outstanding performance in any language, perfectly conveying Juliette's dislocation from the world she finds herself in - but especially impressive as it is delivered in Scott Thomas' second tongue.
And even if her accent is not perfect - my French is certainly not good enough to judge but at one point the film goes out of its way to explain why she speaks differently from her sister - her acting would surely satisfy even the most pedantic Frenchman.